


How the Grunkle Stole Summerween

by EaglePursuit



Series: Another Summer's Sunny Days [7]
Category: Gravity Falls
Genre: Crystal - Freeform, Dana - Freeform, Dipcifica, F/M, Gradual Dipcifica, Post-Gravity Falls, Returning to Gravity Falls, Short, Teenage Dipper Pines, Teenage Dipper Pines and Mabel Pines, Teenage Mabel Pines, Teenage Pacifica Northwest
Language: English
Status: Completed
Published: 2020-07-02
Updated: 2020-07-02
Packaged: 2021-03-05 02:02:09
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,084
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25036699
Author URL: https://archiveofourown.org/users/EaglePursuit/pseuds/EaglePursuit
Summary: Part 7 of the Another Summer's Sunny Days series. Mabel and Pacifica host a Summerween costume party while Ford, unaware of the holiday, tests out a new scientific instrument
Relationships: Dipper Pines/Original Female Character(s), Pacifica Northwest/Dipper Pines
Series: Another Summer's Sunny Days [7]
Series URL: https://archiveofourown.org/series/1792519
Kudos: 17





	How the Grunkle Stole Summerween

**Author's Note:**

> Based on: Disney’s Gravity Falls  
> Created by: Alex Hirsch
> 
> Beta readers: my wife & PK2317  
> Art by: KID | @KIDWMA

How the Grunkle Stole Summerween

“No, Crystal. They don’t reschedule Halloween. They still have it in the Fall. They do Summerween in  _ addition _ to Halloween,” Dipper explained patiently, sitting on a lawn chair on the roof platform of the Mystery Shack. He had his phone pressed to the side of the werewolf mask he was wearing, which made it slightly hard to hear Crystal.

“I just don’t understand why they do it twice,” Crystal said exasperatedly.

“Because it’s fun?” he ventured. “People do all the usual Halloween stuff; dress up, trick-or-treat, go to costume parties, and do pranks. Only, it’s warm out, nobody has school, and the sun sets later. Oh, and pumpkins aren’t ripe yet, so people carve watermelons.”

“I guess I just don’t see the appeal,” she yielded. “I haven’t worn a Halloween costume since I was nine.”

“Well, that’s what we’re doing tonight. Mabel and one of our friends are throwing a costume party at the high school gym.”

“Just one? Based on your stories, Candy and Grenda are usually both involved,” Crystal pointed out.

Dipper slouched back in the chair. “It’s actually not either of them. It’s Pacifica, the one whose old house we burned down.”

“I thought she and Mabel didn’t like each other.” She was confused.

“They didn’t much last summer. But since the fire, they’ve been getting along. Anyway, I need to get going. I’ll send you a picture of my costume when I get into town. Wifi still isn’t working here. I miss you.”

“I miss you too, Mason. Bye,” she replied.

* * *

“You guys ready to leave yet?” Grunkle Stan bellowed in the living room with the keys to the Stanleymobile in his hand.

“Om weddy,” slurred Mabel through her plastic vampire teeth. She wore her tuxedo sweater, black leggings under a black skirt, and a collared cape.

“I’m ready too.” Dipper emerged from the gift shop where the ladder to the roof was. His wolfman mask was complemented by ripped jeans and a red flannel shirt equipped with a panel of fake chest fur below his throat.

Stan looked at the pair in confusion. “I might be way off base here, but don’t you two usually do a theme or something?”

“Mabel’s been reading this book series.” Dipper rolled his eyes. “I guess werewolves and vampires are a thing now.”

Mabel blew a slobbery raspberry. “Whadehwer. Ith tho womanthic.”

“Yeesh.” Stan wiped some spittle off his floral print Hawaiian shirt. “Let’s just get outta here.”

“Bye, Grunkle Ford!” The teens waved to him. He was sitting at the table in the living room, absorbed in a project consisting of an assortment of random parts and tools scattered around him.

“Have fun, kids.” He didn’t even look up.

“What are you working on?” Dipper picked up a long strut and examined it.

“I’m assembling a bionic exoskeleton I’ve had in storage. I just built a new helmet with a suite of anomaly sensors, and I want to use the exoskeleton to go test it,” explained Ford as he test fit some pieces together. “Unfortunately, I seem to have lost the instructions.”

Dipper examined the other parts on the table with eagerness. “If you’re still working on it when I get back from the party, I’ll give you a hand.”

“I’m hoping to have it put together sooner than that. Have a good time.” Ford grunted and squeezed his eyes shut as he tightened a bolt with a hex key.

Stan led Dipper and Mabel out to his old car. “You know, I used to sell Summerween costumes here; until the Summerween Superstore moved in and cut into my profit margins. It was a great way to get rid of the leftover costumes from Ye Olde Mystery Shack Renaissance Faire.”

“You put on a Renaissance Faire?” Dipper asked in surprise.

“I did until the health department shut it down. Apparently, ya hafta ‘refrigerate the turkey legs so they don’t spoil,’” —Stan used air quotes— “I say rancid food gives it an authentic medieval atmosphere.”

* * *

Dipper and Mabel walked into the high school gymnasium. The bleachers had been retracted to the walls and the basketball hoops were pulled up to the rafters. Streamers were hung on the sides of the gym everywhere Pacifica and Mabel could reach with a short ladder; some were even hanging from the rafters, care of Mabel and her grappling hook. Pacifica had set out a selection of hors d'oeuvres and soda on tables. There was also a dance floor set up and Soos was DJing from another table nearby. A few dozen local junior highers milled around, talking and laughing.

Mabel took out her fangs and pointed. “Oh, there’s Paz!”

Dipper turned his eyes in the direction she indicated and his mouth dropped open. Pacifica was wearing a figure-hugging black cat costume with white fur around the neckline and wrists, and a long fluffy tail. It was accessorized by a loose belt sitting askew on her hips, a lacy domino mask, a pair of cat ears, and a hot pink collar. She was making conversation with another girl who was wearing a witch costume.

Mabel giggled at his reaction and nipped his arm with the plastic teeth in her hand. “Pick your jaw up off the floor, you wolfman. You’ve already got a girlfriend.”

Pacifica noticed them and waved, prompting Dipper to regain his composure. “Ugh! Mabel, I wasn’t staring. I was just...taken off guard, is all.”

“Suuuuure you weren’t, bro-bro.” She towed him through the crowd towards her cohost.

“Hi, Mabel, Dipper!” Pacifica greeted them. She accepted a friendly hug from Mabel. “It’s a full turnout like we expected!” She was in a much better mood than the last time Dipper had seen her. He attributed this to the party atmosphere; she was in her element.

“And guys, this is my classmate, Dana.” She introduced the brown-haired girl in the witch costume that consisted of a black sack dress, black boots, and a pointed hat. She also wore a black domino mask, much plainer than Pacifica’s. Dipper noticed she had a distinctive cleft chin. “Dana, these are my friends, Mabel and Dipper.”

“Nice to meet you,” the twins said in unison.

Dana smiled excitedly, “Oh, my gosh, I’ve heard so much about you guys!. I really admire what you did in N.M.A.T.”

Mabel gave Dipper a subtle nudge. “Um, Pacifica, can I talk to you for a second?” he asked. The pitch of his voice quavered with a hint of anxiety. 

“Sure, Dipper.” Pacifica noticed his uneasiness and smirked in amusement. “What’s up?”

Mabel subtly pulled Dana away to distract her with adventurous anecdotes from last summer.

“I uh… realized you were right the other day,” Dipper cringed. “I should have been a better friend and stayed in touch. Mabel told me it was pretty rough for you, and I’m sorry. Can I have your number so I can text you?” He pulled his phone out of his pocket.

“Puh-lease. I know Mabel put you up to this, but of course you can.” She casually snatched his phone and keyed in her contact info, then topped it off with a skillfully taken costume selfie. Before she handed it back, she sent herself a text with his phone so she would have his number as well. “You better text me now. Or I’ll have to yell at you again.” She slapped the phone against his chest playfully.

* * *

Ford adjusted the last straps around his legs. The exoskeleton fit more tightly than it did thirty years ago. Overall, it increased his height to nearly twelve feet, and his arm span to a similar distance. The suit was designed to operate in both bipedal and quadrupedal modes with all four limbs able to both bear weight and grasp for maximum mobility and utility.

He knew from memory that the additional reverse joints several feet below his legs would take some getting used to, so he took a few practice laps around the yard before leaping to the roof of the Mystery Shack and backflipping down. Finally he twisted the control sticks inside the mechanical arms and gently lifted his brother’s pride and joy, the  _ Stan of War II _ , off its trailer and held it overhead. He spun it three hundred and sixty degrees before deftly setting it down again right where it had been.

“Perfect.” Ford smiled to himself in satisfaction. He walked the few long strides back to the porch and squatted the exoskeleton down so he could reach the new helmet with his human hands. It was an oversized ovoid apparatus prickling with antennas and other sensors. He slid it over his head and plugged it into the exoskeleton’s power supply. The interior of the helmet lit up as it initiated its start-up procedure.

Ford turned his head left and right. A pair of phased array antennas mounted on top turned in sync with his head, giving him the appearance of a moth. They fed data to a bank of transistors, which in turn displayed them on a virtual heads up display in front of Ford’s face. His vision through the front visor was augmented with both an ambient light amplifier and an infrared camera.

He stood up too quickly and banged the helmet on the eave of the roof. “Blast it!” he cursed.

He pulled the helmet back off and inspected the side. One of the anomaly detectors, a graphene rod with a spun metal sphere at the end and a helical wire wrapped around it, was bent, but appeared to be operational. He placed the helmet back on his head and ran a diagnostic program, which read no errors.

Rising more carefully, he turned and began to sprint towards town. The exoskeleton allowed him to move with the grace and speed of a gazelle, eating up the half mile to the edge of town in seconds. Only once did a car pass. Ford leaped into the canopy of the forest, traversing from treetop to treetop until it was out of sight.

As he approached town, he initialized the detection array, and the anomaly readings went off the charts, pinging in every direction. Ford reached up and gave the helmet a few taps on the side; the numbers barely moved. “Wow, this is unbelievable,” he muttered. “This town is more anomalous than I ever realized.”

He moved into the yard of a house to investigate the nearest anomaly. There was nothing immediately unusual about the location that would bely the activity level on his sensors, just a regular house with a tree in its front yard.

He began scanning near the tree with the helmet when a zombie leaped at him out of the branches, shaking ominously with glowy yellow eyes. He reacted with a quickness that was forged by decades wandering between hostile dimensions. The exoskeleton’s metal clawed hand grabbed the undead creature, slamming it into the tree and crushing its skull with satisfying ease, almost like it was made of cheap plastic. “These things are surprisingly sticky,” Ford remarked as the remains of the zombie stubbornly clung to the exoskeleton’s appendage, as if by unseen strings. He gave it a few good shakes and the pieces fell to the ground.

He heard a commotion coming from inside the home. “Those people will never know how close they came to becoming zombies themselves,” he growled, “but I’d better keep moving.

* * *

Dipper only knew a handful of people at the Summerween party, so after he said hello and made small talk with them he ended up sipping a can of soda and chatting with Soos while the latter played knock-offs of popular dance songs with low or no licensing fees.

He stopped to watch Mabel and Pacifica work the crowd. The duo were acting as a well-oiled party-hosting machine, greeting guests and encouraging them to take to the dance floor or introducing them to others. They had even dragged a few reluctant boys out on the dance floor themselves before resuming their greeting patrol.

Despite standing close enough to Soos’ speakers to cause his parents, had they been present, to warn him about permanent hearing loss, he heard an ominous wail over the thumping bass.

“Hey, Soos,” Dipper asked, yelling over the music, “do you have your finger on the siren sound again?”

“Nah. I think the cops are here for reals, dawg. That’s how you know your party is off the hoooook!” Soos pushed a key on his keyboard that triggered the foghorn sound effect. “Whoops! That was supposed to be ‘Yeah!’.”

“Keep playing. I’ll get the girls and see what they want to do.” Dipper pushed through the crowd on the dance floor and found Mabel with Pacifica in the middle of a throng of bouncing teens. “Hey, I think the police are here!” 

Pacifica rolled her eyes. “Ugh, why are they bugging us? I made a reservation.”

“Let’s just go outside and talk to them,” suggested Mabel. The trio made their way out the wide double doors, into the parking lot where they found a patrol car marked with Roadkill County Sheriff.

Sheriff Blubs and Deputy Durland were sitting in their car with the windows down, talking on their radio. “Dispatch, we’ve been getting false sightings all summer,” complained Blubs. “Can’t we just chalk this one down as another one?”

“Negative, Sheriff,” replied a tinny female voice. “There have been dozens of reports tonight all over town. The most recent cluster is in the vicinity of the high school.”

The teens approached the officers’ car. “Is there a problem with our party, Sheriff?” Pacifica asked directly.

Blubs rested his arm on the window sill and tipped his hat. “Not as such, little missy.”

“We’re just checking out some reports of a strange creature in the area. Some are calling it an alien,” Durland added with a patronizingly spooky tone.

Pacifica gave him a nonplussed look. “Okay, we’re going to go back inside.”

Dipper caught a flash of movement out of the corner of his eye and jumped. “Wait, what’s that?” He pointed to a large, unfamiliar silhouette on the roof of a nearby house.

Blubs pointed the patrol car’s spotlight at the shape. The beam of light caught the long back leg of a large creature just as it leaped away. It was articulated in an unnatural way. Blubs manipulated the spotlight, tracing the arc of the jump to its ending point and trained it on the creature as it ripped apart an inflatable lawn decoration. It had long arms and legs with claws, multiple reflective eyes, and moth-like antennae on its bulbous head.

“Aaaagh! It is an alien!” screamed Durland. “What do we do?” He and Blubs screamed together. 

The alien shielded its face from the spotlight and leaped away again.

Dipper leaned casually against the warm hood of the patrol car. “Why don’t you let us take care of it?”

Blubs eyed him skeptically. “You kids…handle something like that?” 

“Seriously!?” Dipper glared at him. “You know we saved the whole universe from Bill—”

“Hey now! Never mind all that!” Blubs cut him off threateningly.

Mabel held up her hands and attempted to placate them. “Okay, okay. Are you two hungry? Thirsty? Why don’t you go inside and enjoy some horse divorce and soda?”

“She means hors d'oeuvres,” corrected Pacifica.

Durland scratched the back of his neck. “I am kinda parched from all that screaming.” 

“Alright, let’s do it.” agreed Blubs. “I didn’t want to chase that thing down anyway.” The two scrambled out of the running patrol car. Durland attempted a stylish slide over the hood, but only made it halfway and had to awkwardly crawl across the hot metal. Blubs paused a second to wait for him, then they headed into the gym.

Mabel pulled out her grappling hook as soon as the two officers were out of view. “I’m going to chase it over the rooftops!”

“Okay,” agreed Dipper, “keep me informed of where it’s going.” 

Mabel fired her grappling hook towards the most recent place they had seen the alien and disappeared into the darkness. Dipper and Pacifica, alone, regarded each other awkwardly for a moment. “Do...you want to go back in and host your party while Mabel and I deal with this?”

She shrugged. “Uh, nah. This sounds like more fun.” 

“You  _ want _ to come along?” He was mildly surprised.

She ran her hand along the roof of the police car and shot him a mischievous grin. “You know, Father would be very upset if we were to take this thing for a joyride. It might ruin his reputation.”

Dipper smirked back at her conspiratorially, “Can you drive? I’ll coordinate with Mabel.”

“Sure.” She climbed in behind the wheel and adjusted the seat. Dipper slid into Durland’s spot. They sped off with the roof lights flashing.

“So, uh, how  _ do _ you know how to drive, anyway?” asked Dipper as they sped down residential streets with alarming velocity.

“Father’s always gone on business, lobbying senators and stuff, right?” she reminded him.

“Uh, yeah.”

“So, I borrow his SUV when Mother isn’t paying attention. The windows are so tinted, no one can tell who’s driving. ” She frowned furiously. “It’s payback for when they ground me.”

Dipper glanced at his phone. “Mabel says it’s over on Jefferson now.” Pacifica yanked the steering wheel and spun the tires, drifting the patrol car through a left turn.

* * *

Ford stopped at a distance to observe the next anomaly. Nearly every one he investigated turned out to be some kind of monster, from zombies to mummies. To compound the problem, hordes of miniature monsters were patrolling the sidewalks. He shuddered to imagine what it would be like to be swarmed by them. Fortunately, they were easily avoided. He analyzed the site with his infrared cameras; no sign of anything alive.

He leaped a hundred feet in a single bound and landed in someone’s yard, right next to a gazebo where his sensors said the anomaly was. He looked around; nothing was approaching.

“Finally, a good spot to check,” he muttered. That’s when the giant spider dropped from the roof of the gazebo on his helmet. He flailed his arms and managed to swat it away. It swung back around on its webbing. Ford pulled his ray-gun out of his holster and blasted it.

An alarm sounded in his ear and a warning lit up on his heads up display:  **_Incoming_ ** . Ford glanced behind him and the infrared camera picked up a bright, warm body rushing towards him through the air. He switched to night vision and picked out a cape whipping in the wind and something resembling a tuxedo. “Aha, a vampire. It’s pretty warm for the undead; must have fed recently.”

It gained on him in short, speedy bursts of flight. He aimed his ray-gun at the vampire. “Darn thing’s too erratic. I’ll never hit it,” he cursed and holstered the weapon. “But I bet I can outrun it.” He turned and leaped onto a nearby lamppost, then took off down the street.

* * *

“It’s on Wisconsin now; Mabel is estimating it will cross East Street in about 60 seconds,” Dipper reported. 

Pacifica turned hard onto East and floored it, sending the RPM indicator deep into the red zone. She gritted her teeth. “We’ll almost make it.”

* * *

Ford was getting scared. He pushed the exoskeleton as hard as it could go, but he couldn’t lose the vampire. It dogged him like some inexorable curse. Every trick he could think of to lose it didn’t work.

Another alarm beeped in his ear and an indicator popped up on the heads up display that read:  **_Law Enforcement_ ** . He caught a glimpse of flashing lights out the corner of his left eye. The sight of the police car gave Ford an idea. If he jumped low over it, he might lose the vampire, or the police would stop and help him apprehend it. He slowed a little and timed his jump perfectly. The leg actuators launched him into the air. 

* * *

Dipper climbed out the passenger window and yelled over the wind noise, “When I bang on the roof, turn hard left and slide it sideways.” 

Pacifica nodded, concentrating too hard to speak.

Half a minute later he called out, “I see it!” 

Pacifica looked out the windshield and made out a dark shape bounding off the sidewalk on the right side of the street. Dipper banged on the roof. She turned the steering wheel left with one hand while jerking the parking brake back. Tires squealed. The vehicle lurched violently and nearly turned on its side. A half a box of doughnuts and a collection of disposable coffee cups emerged from under the seats and tumbled towards the passenger side of the patrol car.

* * *

Just as he was about to sail over the hood of the police car, he saw it jerk sideways and a werewolf catapult off the passenger side towards him. There was nothing he could do to alter his own trajectory. The hairy creature tackled him around the middle, knocking the breath out of him, and causing them both to crash to the street.

Ford tried to get up, but the exoskeleton groaned and wobbled. The impact had damaged several joint servos and gyroscopic balance sensors. The werewolf struggled to its feet as well and moved to block him from crawling away. The vampire arrived a second later, firing some kind of restraint snare that toppled Ford and the exoskeleton back to the pavement.

The police car pulled up and destroyed his last hopes of being saved. Ford squinted as the werewolf, the vampire, and now a third figure, some kind of humanoid cat, were silhouetted in the blinding glare of the headlights. Ford gritted his teeth defiantly as they approached.

* * *

Dipper, Mabel, and Pacifica approached the alien as it struggled against the rope of Mabel’s grappling hook. Dipper gawped in amazement. “Whoa, check it out. It’s a guy in some kind of robotic suit.”

Mabel booped the front of the man’s helmet with a finger. “Do you think it’s Old Man McGucket?”

“Ugh, that would figure. Let’s pull that bug head off and find out,” Pacifica said derisively, attempting to hide the exhilaration in her voice.

Dipper grabbed the edges of the strange helmet and lifted it away. “Grunkle Ford!” Dipper and Mabel said in unison. Mabel quickly retracted the grappling hook off of him.

“What’s he doing here?” asked Pacifica.

“I was out investigating anomalies, like I told Dipper and Mabel I would be doing. Do you know how dangerous it is out here tonight? There are monsters everywhere!” Ford paused for a second. “Wait, why are you dressed up like monsters?”

“Grunkle Ford,” Mabel laughed, “it’s Summerween!”

“Can I ask why you have a police car?” asked Ford, suddenly confused.

“Well, um...Hey, why were you destroying Summerween decorations!?” Dipper shot back.

Ford looked around guiltily. “I think my helmet may still have a few bugs in it.” 

“I guess this mystery is solved.” Dipper said. 

Mabel elbowed him in the ribs. “Uh, Dipstick...we should probably get back to the party before Sheriff Blubs and Deputy Durland realize their car is missing.”

“I don’t suppose you can give me a ride?” Ford started unstrapping the exoskeleton from his body. “I’m not going anywhere now that this suit is ruined.”

“Right. Of course. Um, sorry about that,” Dipper apologized nervously. “And you should probably drive. None of us are actually sixteen yet.”

* * *

Sheriff Blubs stood in the middle of the dance floor. A large group of teens formed a circle around him, chanting his name. “Hit it, DJ!”

Soos started a nineties era hip hop song and Blubs felt the music flow through him. He picked up the beat and footrocked for half a minute. Then he did a fishtail sweep drop and transitioned into windmills to wild applause.

“That’s my Blubs!” Deputy Durland put two fingers in his mouth and whistled.

A partygoer in a grayish-green alien costume with a large, bulbous head and spindly arms slipped away from the group and made their way to the exit, passing Mabel, Pacifica, and Dipper as they came back in.

“Kbefert acfjnwe aferkqw,” they spoke into a wrist-mounted device.

“That’s an impressive costume,” Dipper commented to the girls. “Who is that guy?”

“I have no idea,” Pacifica replied.

ZIGCKWVTUVIMMJPJOMQOELX

YHJBLUVXIWVVXMHPADMBTZELX

UVIIGAZAKKGAOAAGJWVMVLHT

UWACZTPKIILCYAJXVAAZEQS

Be sure to read the next adventure:

Game of Scones


End file.
